Very Low Power Cockcroft-Walton Voltage Multiplier for RF Energy Harvesting Applications

A device was required that could harvest the electromagnetic energy present in ambient radio frequency (RF) signals. A part of this device must convert the AC RF signal received by the antenna into a DC signal that can be used in an embedded application. Since the RF signal amplitude is small, it must first be amplified and rectified to become a usable signal. The Cockcroft-Walton voltage multiplier is a subsystem of the design which ideally converts a 100 mV AC signal coming from the antenna to a 350 mV DC signal. The output of the voltage multiplier is used to power another subsystem. At 10 MHz, the Cockcroft-Walton multiplier was able to output a DC voltage of 350 mV given an AC input signal of 140 mV. The results of the testing show verifiable proof-of-concept that the Cockcroft-Walton voltage multiplier has the potential to be used for low power RF energy harvesting applications

Mobile Device Policies in Archive Reading Rooms

Humanities scholars increasingly use mobile devices such as laptops, iPhones, and iPads in their professional lives. We are exploring the opportunities for employing such devices for supporting scholarly activities in archive reading rooms. As a first step in this process, we are studying how reading room policies related to the use of technological devices impact scholars’ interaction with the source materials in terms of capturing, organizing, note taking, and record keeping for future use of found materials. We studied the policy documents made available by thirty archives and complemented the results by soliciting the perspectives of administrators who craft these policies and scholars who use these archives. We present our analysis and an early prototype of a policy awareness mobile application called AMTracker.Informatio

Ordering the Reidemeister moves of a classical knot

We show that any two diagrams of the same knot or link are connected by a sequence of Reidemeister moves which are sorted by type.Comment: This is the version published by Algebraic & Geometric Topology on 18 May 200

Drug Policy and the HIV Pandemic in Russia and Ukraine

Over the past three years Russia and Ukraine have experienced one of the fastest growing HIV pandemics in Europe. In contrast to other parts of the world, the main driver behind the rate of infection is injecting drug use. Recent government policies have placed a heavy emphasis on reducing availability and on harsh punishments for drug users. This approach has not succeeded in significantly reducing the level of drug use. It has pushed the drug scene underground and increased risky behaviours among vulnerable groups. In the absence of measures to reduce infections and reverse the rate of transmission, the long-term impact of HIV/AIDS on population growth and economic development is likely to be grave

First-Generation College Students & Campus Resources

The purpose of this research was to analyze how campus resources at Valparaiso University affect first-generation college students. Specifically, this study looked at the effect campus resources have on feelings of belonging on campus and academic success. First generation college students are defined as students whose parents have not obtained a four-year degree. This study used a questionnaire that was emailed to every known first-generation college student at Valparaiso University. This consisted of five sections: demographics, campus resource use, the campus community, academic preparedness, and experience. The use of campus resources section used a Likert scale to see how often students used different campus resources. The campus community and academic preparedness sections also used a Likert scale to see how much students related to questions such as, “I feel like I fit in at Valpo”. Finally, the experience section allowed for students to write in specific challenges they have faced on Valparaiso University\u27s campus. These results can help further develop the Persistence and Success Program (PSP), a first-generation college student program on campus

NJ and PA Once Again: What Happened to Employment When the PA-NJ Minimum Wage Differential Disappeared?

Card and Krueger's analysis of the impact of the 1992 increase in the NJ state minimum wage is very well known and still controversial. Interestingly, the original NJ-PA natural experiment was followed by another one involving the same two states, an experiment that has not yet been noted or examined. In 1996 and 1997, the federal minimum wage was increased in two steps, from $4.25 to$5.15, thereby increasing the minimum wage by $0.90 in PA but by just$0.10 in NJ. We use CPS data from 1995 and 1998 to examine the impacts on employment, using difference-in-difference and difference-in-difference-in-difference estimators that exploit within- state and between-state comparisons. We find consistent evidence that employment of “at-risk” groups was negatively impacted in PA relative to other groups in PA and to comparable groups in NJ.Minimum Wage, Card-Krueger

Longitudinal Study of Lanana Creek

A longitudinal study was done to collect data on the various conditions of LananaCreek in Nacogdoches, Texas over a seven week span from September 14 to November 2, 2018. The part of the creek studies is a 3.5 mile stretch from East Austin Street to Hoya Soccer Complex, mostly located on the campus of Stephen F. Austin State University. There were 6 different testing sites selected along this expanse. Collection of samples was performed by the General Chemistry I Honors class as part of the laboratory experience. Once collected, the samples were transported back to the lab for testing. The tests performed on the samples included determination of the pH, total solids, total dissolved solids, water hardness, anion concentration, and alkalinity. Each of these tests analyzes for a different parameter that is essential in evaluating the health of the ecosystem as a whole and gives a good reflection of the overall health of the creek’s surrounding environment. The results were compared to EPA standards. During the testing period, there were significant rain events generating variable results after each sampling, but the overall study shows that LananaCreek is healthy

Designing a task-based critical listening construct for listening assessment

This study analyzed a task-based construct of critical listening in an academic listening test for placement purposes in a North American university English for Academic Purposes program. As the ability to listen critically in English is one of the outcomes for the program, it is necessary to utilize a placement instrument that can adequately measure this ability. Buck (2001) claims that one way of approaching this idea of critical listening in listening assessment is through the use of tasks that mirror the uses and functions an examinee will encounter in authentic situations. Using Rasch model analysis, this study first examined the current form of the test to identify how items are functioning and whether or not different, distinct constructs are present in the test. The test was revised using new pilot items based on a task-based model, and then analyzed again to determine the extent this construct was represented in the instrument. Based on these analyses, recommendations are made about the effectiveness of the test and the form further revisions of the test might take in future administrations

The Genetic Epidemiology of Purging Disorder, Anorexia Nervosa, and Obsessive Compulsive Personality Disorder

Although a variety of factors influence the development of eating disorders, genetic factors contribute notably to their etiology. Understanding genetic factors associated with eating disorders is important, as they can influence how these disorders are recognized, researched, and treated. This dissertation included two studies addressing important questions within the fields of eating disorders and genetics; specifically, Study 1 addressed the prevalence and heritability of purging and purging disorder in a population-based sample of female twins from the United States; and Study 2 investigated the nature of the co-morbidity between anorexia nervosa and obsessive compulsive personality disorder in a population-based sample of female twins from Norway. Twin methodology was applied for both studies. Univariate analyses, a bivariate Cholesky decomposition, and an item-factor modeling approach were used. Results from Study 1 revealed estimates of 3.0%, 3.4%, 3.7%, and 11.5% for self-induced vomiting, laxative and diuretic abuse, and excessive exercise, respectively. Laxative abuse was more strongly influenced by common environmental effects, while liability to excessive exercise was more strongly influenced by common genetic factors. Due to insufficient data, an item-factor model of purging disorder did not yield conclusive results. In Study 2, the phenotypic correlation between anorexia nervosa and obsessive compulsive personality disorder was 0.08. A bivariate Cholesky decomposition revealed that an AE-AEre model best fit the data, indicating that additive genetic effects moderately contribute to both anorexia nervosa and obsessive compulsive personality disorder individually but that these genetic influences are not shared between the two disorders. In addition, this model suggests that the slight overlap in liability between the two disorders is entirely accounted for by unique environmental effects and error. These results provide preliminary findings on important topics within the field of eating disorders and genetics research. Further study of the heritability of purging and purging disorder, as well as the nature of the co-morbidity between anorexia nervosa and obsessive compulsive personality disorder, is needed in large population-based samples. Better understanding the etiology of disordered eating and frequently co-occurring diagnoses, both at the diagnosis and symptom level, might have the potential to inform classification and treatment